Gas chromatography (GC) is a chromatographic technique used to separate and analyze compounds that can be vaporized without decomposition. Mass spectrometry (MS) is an analytical technique used to measure mass-to-charge ratios of charged particles in the form of molecules, molecule fragments, and/or atoms, which can be generated from ionized sample materials. MS can be used to determine particle masses, elemental composition, and/or chemical structures of sample material. Gas chromatography-mass spectroscopy (GC-MS) combines a gas chromatograph with a mass spectrometer. Together, gas chromatography and mass spectroscopy often provide a finer degree of sample identification than either technique can provide separately. For instance, mass spectrometry generally requires a pure sample, while gas chromatography may not be capable of differentiating between different molecules with the same retention times. However, because it is unlikely that two different molecules will have the same behavior with respect to both a gas chromatograph and a mass spectrometer, there can be an increased certainty that a particular analyte is present in a sample of interest when an identifying mass spectrum appears at a characteristic retention time in a GC-MS analysis.